1. Field of the Invention
The present invention is directed to a manufacturing method for rod-shaped silicon structures in the nanometer (nm) range, particularly for the manufacture of field emission electrodes.
2. Description of the Related Art
It is frequently necessary to produce cylindrical or rod-shaped structures in the nm range in the field of microelectronics. For example, such structures are particularly required in field emission microscopy. A cold cathode field emitter requires structures having a magnitude on the order of a few nanometers. Applications for quantum elements, for example luminescent structures, are also conceivable having diameters from four nm. The quality factors of various cold cathode emission tips are compared to one another dependent on their geometrical shape with respect to their current yield at a specific electrical voltage in the publication by T. Utsumi in IEEE Transactions on Electron Devices 38, 2276-2283 (1991). A cylinder rounded off at the tip has ideal geometry for a field emission tip. Such a structure is superior both with respect to stability as well as in terms of current yield by a factor of 3-10 compared to previously employed conical emitters. Cylindrical structures will therefore most likely become more significant in the future instead of the previously used, conical emitters. The comical emitters are, for example, produced by etching, specific vapor-deposition techniques or selective epitaxy. Sharpening such structures on silicon in an oxidation process is known, whereby anisotropic oxidation at the edges and tips is utilized.